Method and apparatus for spine joint replacement

ABSTRACT

A prosthesis for the replacement of the cartilaginous structures of a spine motion segment is described. The prosthesis comprises an intervertebral disc prosthesis in combination with a facet joint prosthesis.

REFERENCE TO PENDING PRIOR PATENT APPLICATIONS

[0001] This patent application claims benefit of:

[0002] (1) pending prior U.S. Provisional Patent Application Serial No.60/273,031, filed Mar. 2, 2001 by E. Marlowe Goble et al. for TOTALSPINE JOINT REPLACEMENT (Attorney's Docket No. MED-3 PROV);

[0003] (2) pending prior U.S. patent application Ser. No. 09/726,169,filed Nov. 29, 2000 by E. Marlowe Goble et al. for FACET JOINTREPLACEMENT (Attorney's Docket No. MED-1);

[0004] (3) pending prior U.S. patent application Ser. No. 09/736,103,filed Dec. 13, 2000 by E. Marlowe Goble et al. for MULTIPLE FACET JOINTREPLACEMENT (Attorney's Docket No. MED-2); and

[0005] (4) pending prior U.S. patent application Ser. No. 09/797,309,filed Mar. 01, 2001 by T. Wade Fallin et al. for PROSTHESIS FOR THEREPLACEMENT OF A POSTERIOR ELEMENT OF A VERTEBRA (Attorney's Docket No.MED-4).

[0006] The four above-identified patent applications are herebyincorporated herein by reference.

FIELD OF THE INVENTION

[0007] This invention relates to surgical devices and methods ingeneral, and more particularly to surgical devices and methods forreplacing a damaged, diseased, or otherwise painful spinal joint.

BACKGROUND OF THE INVENTION

[0008] Traumatic, inflammatory, metabolic, synovial, neoplastic anddegenerative disorders of the spine can produce debilitating pain thatcan have severe socioeconomic and psychological effects.

[0009] One of the most common surgical interventions today isarthrodesis, or spine fusion, in which two or more adjacent vertebralbodies are fused together in order to alleviate pain associated with thedisc(s) located between those vertebral bodies. Approximately 300,000such procedures are performed annually in the United States alone.Clinical success varies considerably, depending upon technique andindications, and consideration must be given to the concomitant risksand complications.

[0010] For example, while spine fusion generally helps to eliminatecertain types of pain, it has also been shown to decrease function bylimiting the range of motion for patients in flexion, extension,rotation and lateral bending. Furthermore, it is believed that spinefusion creates increased stresses on (and, therefore, accelerateddegeneration of) adjacent non-fused motion segments. Additionally,pseudoarthrosis, resulting from an incomplete or ineffective fusion, mayreduce or even totally eliminate the desired pain relief for thepatient. Also, the fusion device(s) used to effect fusion, whetherartificial or biological, may migrate out of the fusion site, therebycreating significant new problems for the patient.

[0011] Recently, attempts have been made to recreate the naturalbiomechanics of the spine through the use of an artificial disc.Artificial discs are intended to restore articulation between vertebralbodies so as to recreate the full range of motion normally allowed bythe elastic properties of the natural disc, which directly connects twoopposing vertebral bodies. Various artificial discs are described byStefee et al. in U.S. Pat. No. 5,071,437; Gill et al. in U.S. Pat. No.6,113,637; Bryan et al. in U.S. Pat. No. 6,001,130; Hedman et al. inU.S. Pat. No. 4,759,769; Ray in U.S. Pat. No. 5,527,312; Ray et al. inU.S. Pat. No. 5,824,093; Buttner-Janz in U.S. Pat. No. 5,401,269; andSerhan et al. in U.S. Pat. No. 5,824,094; all which documents are herebyincorporated herein by reference. Still other artificial discs are knownin the art.

[0012] Unfortunately, however, artificial discs alone do not adequatelyaddress all of the mechanics of the motion of the spinal column.

[0013] In addition to the intervertebral disc, posterior elements calledthe facet joints help to support axial, torsional and shear loads thatact on the spinal column. Furthermore, the facet joints are diarthroidaljoints that provide both sliding articulation and load transmissionfeatures. However, the facet joints can also be a significant source ofspinal disorders and, in many cases, debilitating pain. For example, apatient may suffer from arthritic facet joints, severe facet jointtropism or otherwise deformed facet joints, facet joint injuries, etc.There is currently a lack of good interventions for facet jointdisorders. Facetectomy, or the removal of the facet joints, may providesome relief, but it is also believed to produce significant decreases inthe stiffness of the spinal column (i.e., hypermobility) in all planesof motion: flexion and extension, lateral bending, and rotation.Furthermore, problems with the facet joints can also complicatetreatments associated with other portions of the spine. By way ofexample, contraindications for artificial discs include arthritic facetjoints, absent facet joints, severe facet joint tropism or otherwisedeformed facet joints.

[0014] A superior vertebra with its inferior facets, an inferiorvertebra with its superior facets, the intervertebral disc, and sevenspinal ligaments together comprise a spinal motion segment or functionalis spine unit. The spinal motion segment provides complex motion alongthree orthogonal axis, both in rotation (lateral bending, flexion andextension, and axial rotation) and in translation (anterior-posterior,medial-lateral, and cranial-caudal). Furthermore, the spinal motionsegment provides physiological limits and stiffnesses in each rotationaland translational direction to create a stable and strong columnstructure to support physiological loads.

[0015] As mentioned above, compromised facet joints are acontraindication for disc replacement, due to the inability of theartificial disc (when used with compromised facet joints, or when usedwith missing facet joints) to properly restore the natural biomechanicsof the spinal motion segment. It would therefore be an improvement inthe art to provide a spine implant system that facilitates concurrentreplacement of the intervertebral disc and facet joints where both havebeen compromised due to disease or trauma.

[0016] U.S. Pat. No. Re. 36,758 (Fitz) discloses an artificial facetjoint where the inferior facet, the mating superior facet, or both, arecovered with a cap. This cap requires no preparation of the bone orarticular surfaces; it covers and, therefore, preserves the bony andarticular structure. The capping of the facet has several potentialdisadvantages, however. If the facet joint is osteoarthritic, a cap willnot remove the source of the pain. Additionally, at least in the case ofsurface replacements for osteoarthritic femoral heads, the capping ofarticular bone ends has proven to lead to clinical failure by means ofmechanical loosening. This clinical failure is hypothesized to be asequela of disrupting the periosteum and ligamentum teres femoris, bothserving a nutrition delivery role to the femoral head, thereby leadingto avascular necrosis of the bony support structure for the surfacereplacement. It is possible that corresponding problems could developfrom capping the facet. Another potential disadvantage of facet cappingis that in order to accommodate the wide variability in anatomicalmorphology of the facets, not only between individuals but also betweenlevels within the spinal column, a very wide range of cap sizes andshapes is required.

[0017] U.S. Pat. No. 6,132,464 (Martin) discloses a spinal facet jointprosthesis that is supported on the lamina (which is sometimes alsoreferred to as the posterior arch). Extending from this supportstructure are inferior and/or superior blades that replace the cartilageat the facet joint. Like the design of the aforementioned U.S. Pat. No.Re. 36,758, the prosthesis of U.S. Pat. No. 6,132,464 generallypreserves existing bony structures and therefore does not addresspathologies which affect the bone of the facets in addition to affectingthe associated cartilage. Furthermore, the prosthesis of U.S. Pat. No.6,132,464 requires a secure mating between the prosthesis and thelamina. However, the lamina is a very complex and highly variableanatomical surface. As a result, in practice, it is very difficult todesign a prosthesis that provides reproducible positioning against thelamina so as to correctly locate the cartilage-replacing blades for thefacet joints.

[0018] Another approach to surgical intervention for spinal facets isdisclosed in International Patent Publication No. WO9848717A1 (Villaretet al.). While this publication teaches the replacement of spinalfacets, the replacement is interlocked in a manner so as to immobilizethe joint.

[0019] Thus it will be seen that previous attempts to provide facetjoint replacement have proven inadequate.

[0020] In some circumstances, additional structures of a vertebra besidethe facets may have been compromised by disease or trauma. For example,the lamina, the spinous process and/or the two transverse processes mayhave been compromised by disease or trauma. In such a circumstance, itwould be useful to have a prosthesis which would allow the replacementof the same.

SUMMARY OF THE INVENTION

[0021] One object of the present invention is to provide a spine jointreconstruction assembly that replaces the intervertebral disc and one ormore of the facet joints in order to restore the natural biomechanics ofa spinal motion segment.

[0022] Another object of the present invention is to provide a methodfor reconstructing the spine joint by replacing the intervertebral discand one or more of the facet joints in order to restore the naturalbiomechanics of a spinal motion segment.

[0023] Still another object of the present invention is to provide a kitfor the reconstruction of multiple spine joints to replaceintervertebral discs and facet joints in order to restore the naturalbiomechanics of a spinal motion segment.

[0024] In accordance with the present invention, the preferredembodiment, the intervertebral disc is excised and replaced with anartificial disc. This artificial disc may be a device such as isdescribed by Stefee et al. in U.S. Pat. No. 5,071,437; Gill et al. inU.S. Pat. No. 6,113,637; Bryan et al. in U.S. Pat. No. 6,001,130; Hedmanet al. in U.S. Pat. No. 4,759,769; Ray in U.S. Pat. No. 5,527,312; Rayet al. in U.S. Pat. No. 5,824,093; Buttner-Janz in U.S. Pat. No.5,401,269; and Serhan et al. in U.S. Pat. No. 5,824,094; all whichdocuments are hereby incorporated herein by reference. Alternatively,the artificial disc may be some other artificial disc of the sort knownin the art.

[0025] In addition to replacing the intervertebral disc, at least one ofthe facet joints is replaced in accordance with the apparatus andmethods described hereinafter. Alternatively, the facet joints may bereplaced as described by Fitz in U.S. Pat. No. Re. 36,758; Martin inU.S. Pat. No. 6,132,464; and/or Villaret et al. in International PatentPublication No. WO 9848717A1, which documents are hereby incorporatedherein by reference. Or one or more of the facet joints may be replacedby other apparatus and methods known in the art.

[0026] The present invention has several advantages over the prior art.For one thing, the present invention can provide a complete replacementof all of the articulation surfaces of a spine motion segment: theintervertebral disc and the facet joints. Proper disc height is restoredwhile degenerated facet joints and the underlying painful bone isreplaced. The prosthetic disc and prosthetic facet joints work togetherto reproduce the desired physiological range of motion and to providelow friction articulations, so that adjacent motion segments arereturned to physiological levels of stress and strain. Furthermore,osteophytic growth can be concurrently removed, and the artificial discand facet joint prosthesis together reestablish intervertebral andcentral foraminal spaces to ensure decompression of any nerve structure.Thus, all sources of pain, such as pain associated with osteoarthritis,instability, and nerve compression, are removed while restoring fullfunction of the spine motion segment.

BRIEF DESCRIPTION OF THE DRAWINGS

[0027] These and other objects and features of the present inventionwill be more fully disclosed or rendered obvious by the followingdetailed description of the preferred embodiments of the invention,which is to be considered together with the accompanying drawingswherein like numbers refer to like parts and further wherein:

[0028]FIG. 1 is a perspective view of a portion of the spine;

[0029]FIG. 2 is a dorsal view of the portion of the spine shown in FIG.1;

[0030]FIG. 3 is a lateral view of a spine joint reconstructed inaccordance with one aspect of the present invention;

[0031]FIG. 4 is a dorsal view of the facet joint shown in FIG. 3;

[0032]FIG. 5 is a perspective view of the implanted left inferior facetprosthesis shown in FIGS. 3 and 4;

[0033]FIG. 6 is a perspective view of the left inferior facet prosthesisshown in FIGS. 3 and 4;

[0034]FIG. 7 is a cranial view of the implanted left superior facetprosthesis shown in FIGS. 3 and 4;

[0035]FIG. 8 is a perspective view of the left superior facet prosthesisshown in FIGS. 3 and 4;

[0036]FIG. 9 is a perspective view of an alternate implanted leftsuperior facet prosthesis;

[0037]FIG. 10 is a perspective view of an alternate left superior facetprosthesis;

[0038]FIG. 11 is a lateral view of an alternative reconstructed spinejoint;

[0039]FIG. 12 is a dorsal view of an alternative reconstructed spinejoint;

[0040]FIG. 13 is a perspective view of the implanted left inferior facetprosthesis shown in FIGS. 11 and 12;

[0041]FIG. 14 is a perspective view of the alternative left inferiorfacet prosthesis shown in FIGS. 11 and 12;

[0042]FIG. 15 is a cranial view of the alternative implanted leftsuperior facet prosthesis shown in FIGS. 11 and 12;

[0043]FIG. 16 is a perspective view of the alternative left superiorfacet prosthesis shown in FIGS. 11 and 12;

[0044]FIG. 17 is a perspective view of an alternate bearing surface forthe superior facet prosthesis shown in FIG. 16;

[0045]FIG. 18 is a perspective view of a spine motion segment;

[0046]FIG. 19 is a dorsal view of a bilateral facet joint reconstructedin accordance with the present invention;

[0047]FIG. 20 is a lateral view of the bilateral facet joint prosthesisshown in FIG. 19;

[0048]FIG. 21 is a dorsal view of the implanted inferior bilateral facetprosthesis shown in FIGS. 19 and 20;

[0049]FIG. 22 is an inferior view of the implanted inferior bilateralfacet prosthesis shown in FIGS. 19 and 20;

[0050]FIG. 23 is a ventral view of the inferior bilateral facetprosthesis shown in FIGS. 21 and 22;

[0051]FIG. 24 is a dorsal view of the implanted superior bilateral facetprosthesis shown in FIGS. 19 and 20;

[0052]FIG. 25 is a superior view of the implanted superior bilateralfacet prosthesis shown in FIGS. 19 and 20;

[0053]FIG. 26 is a ventral view of the superior bilateral facetprosthesis shown in FIGS. 24 and 25;

[0054]FIG. 27 is a perspective view of an alternative embodiment of thesuperior bilateral facet prosthesis shown in FIGS. 24 and 25;

[0055]FIG. 28 is a dorsal view of a two level facet joint replacement;

[0056]FIG. 29 is a lateral view of the two level facet joint replacementof FIG. 28;

[0057]FIG. 30 is a dorsal view of the implanted four facet prosthesisshown in FIGS. 28 and 29;

[0058]FIG. 31 is a perspective view of the four facet prosthesis shownin FIG. 30;

[0059]FIG. 32 is a perspective view of an alternative form of inferiorbilateral facet prosthesis;

[0060]FIG. 33 is a perspective view of an implanted superior andinferior unilateral facet prosthesis;

[0061]FIG. 34 is a perspective view of the unilateral facet prosthesisshown in FIG. 33;

[0062]FIG. 35 is a perspective view of a lumbar vertebra;

[0063]FIG. 36 is a perspective view of a novel prosthesis that replacesthe lamina, the four facets, the spinous process and the two transverseprocesses of a vertebra;

[0064]FIG. 37 is an anterior view of the prosthesis shown in FIG. 36;

[0065]FIG. 38 is a perspective view of a vertebra which has beenresected to receive the prosthesis shown in FIG. 36;

[0066]FIG. 39 is a perspective view of the prosthesis shown in FIG. 36mounted to the resected vertebra shown in FIG. 38;

[0067]FIG. 40 is a dorsal view of the prosthesis shown in FIG. 36mounted to the resected vertebra shown in FIG. 38;

[0068]FIG. 41 is a lateral view of the prosthesis shown in FIG. 36mounted to the resected vertebra shown in FIG. 38;

[0069]FIG. 42 is a perspective view of a novel prosthesis that replacesthe lamina, the four facets and the spinous process of a vertebra;

[0070]FIG. 43 is a perspective view of a novel prosthesis that replacesthe lamina, the four facets and the two transverse processes of avertebra;

[0071]FIG. 44 is a perspective view of a novel prosthesis that replacesthe lamina and the four facets of a vertebra;

[0072]FIG. 45 is a perspective view of a novel prosthesis that replacesthe two pedicles, the lamina, the four facets, the spinous process andthe two transverse processes of a vertebra;

[0073]FIG. 46 is a lateral view of the prosthesis shown in FIG. 45;

[0074]FIG. 47 is an anterior view of the prosthesis shown in FIG. 45;

[0075]FIG. 48 is a perspective view of a vertebra which has beenresected to receive the prosthesis shown in FIG. 45;

[0076]FIG. 49 is a perspective view showing the prosthesis of FIG. 45mounted to the resected vertebra shown in FIG. 48;

[0077]FIG. 50 is a perspective view of a novel prosthesis that replacesthe two pedicles, the lamina, the four facets and the spinous process ofa vertebra;

[0078]FIG. 51 is a perspective view of a novel prosthesis that replacesthe two pedicles, the lamina, the four facets and the two transverseprocesses of a vertebra;

[0079]FIG. 52 is a perspective view of a novel prosthesis that replacesthe two pedicles, the lamina and the four facets of a vertebra; and

[0080]FIG. 53 is a perspective view showing an alternative arrangementfor mounting the prosthesis of FIG. 45 to a vertebra.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Disc Prosthesis andSingle Facet Prosthesis

[0081] Referring now to FIGS. 1 and 2, there is shown a superiorvertebra 1 and an inferior vertebra 3, with an intervertebral disc 2located in between. Vertebra 1 has superior facets 43, inferior facets6, posterior arch 35 and spinous process 46. Vertebra 3 has superiorfacets 7, inferior facets 44, posterior arch 36 and spinous process 45.

[0082] Referring now to FIG. 3, in accordance with one aspect of thepresent invention, the intervertebral disc 2 has been replaced by anartificial disc AD. This artificial disc AD may be a device such as isdescribed by Stefee et al. in U.S. Pat. No. 5,071,437; Gill et al. inU.S. Pat. No. 6,113,637; Bryan et al. in U.S. Pat. No. 6,001,130; Hedmanet al. in U.S. Pat. No. 4,759,769; Ray in U.S. Pat. No. 5,527,312; Rayet al. in U.S. Pat. No. 5,824,093; Buttner-Janz in U.S. Pat. No.5,401,269; and Serhan et al. in U.S. Pat. No. 5,824,094; all whichdocuments are hereby incorporated herein by reference. Alternatively,the artificial disc may be some other artificial disc of the sort knownin the art.

[0083] In addition to the foregoing, the left inferior facet 6 ofvertebra 1 has been resected and an inferior facet prosthesis 4 has beenattached to vertebra 1. Similarly, the left superior facet of vertebra 3has been resected and a superior facet prosthesis 5 has been attached tovertebra 3.

[0084]FIG. 4 illustrates a dorsal view of the elements shown in FIG. 3.It can be appreciated that inferior facet prosthesis 4 replicates thenatural anatomy when compared to the contralateral inferior facet 6 ofvertebra 1. Similarly, it can be appreciated that superior facetprosthesis 5 replicates the natural anatomy when compared to thecontralateral superior facet 7 of vertebra 3.

[0085] Turning now to FIG. 5, a perspective view of vertebra 1 withimplanted inferior facet prosthesis 4 is provided. Resection at 31 hasremoved the natural inferior facet 6 at the bony junction between theinferior facet 6 and the posterior arch 35. In this manner, bone painassociated with a disease, such as osteoarthritis, or trauma may beeliminated as the involved bony tissue has been osteotomized.

[0086]FIG. 6 illustrates a perspective view of inferior facet prosthesis4. Surface 8 replicates the natural articular surface of the replacedinferior facet 6. Post 9 provides a means to affix inferior facetprosthesis 4 to vertebra 1. Post 9 is implanted into the interior bonespace of the left pedicle P (FIG. 7) on vertebra 1 and may or may notextend into the vertebral body of vertebra 1 to provide additionalstability.

[0087]FIG. 7 illustrates a cranial view of vertebra 3 with implantedsuperior facet prosthesis 5. Resection surface 32 represents the bonyjunction between the natural superior facet and the posterior arch 35.

[0088]FIG. 8 illustrates a perspective view of superior facet prosthesis5. Surface 36 replicates the natural articular surface of the replacedsuperior facet 7. Post 37 provides a means for affixing superior facetprosthesis 5 to vertebra 3. Post 37 is implanted into the interior bonespace of the left pedicle P (FIG. 7) on vertebra 3 and may or may notextend into the vertebral body of vertebra 3 to provide additionalstability.

[0089] When the total facet joint is replaced, as shown in FIGS. 3 and4, then surface 8 (FIG. 6) articulates with surface 36 (FIG. 8) torecreate the natural biomechanics of the spine motion segment made up ofvertebra 1, vertebra 3, and intervertebral disc 2.

[0090]FIG. 9 illustrates an alternative inferior facet prosthesis 10which is implanted into the interior bone space of posterior arch 35.The interior bone space is accessed from the resection 31.

[0091]FIG. 10 shows details of alternative inferior facet prosthesis 10,including the fin 13 that extends into the interior bone space ofposterior arch 35. Surface 12 replicates the natural articular surfaceof the replaced facet.

[0092] If desired, a corresponding fin construction can be used to forma prosthetic superior facet.

[0093] The surfaces of post 9 (FIG. 6), post 37 (FIG. 8) and fin 13(FIG. 10) may or may not include porous coatings to facilitate boneingrowth to enhance the long term fixation of the implant. Furthermore,such porous coatings may or may not include osteoinductive orosteoconductive substances to further enhance the bone remodeling intothe porous coating.

[0094] Referring now to FIG. 11, there is shown a lateral view of asuperior vertebra 14 and an inferior vertebra 16, with an intervertebraldisc 15 located in between is shown. The left inferior facet of vertebra14 has been resected and an inferior facet prosthesis 18 has beenattached to vertebra 14 by means of a screw fastener 17. Similarly, theleft superior facet of vertebra 16 has been resected and a superiorfacet prosthesis 19 has been attached to vertebra 16 by means of a screwfastener 17.

[0095]FIG. 12 illustrates a dorsal view of the elements of FIG. 11. Itcan be appreciated that inferior facet prosthesis 18 replicates thenatural anatomy when compared to the contralateral inferior facet 22 ofvertebra 14. Similarly, it can be appreciated that superior facetprosthesis 19 replicates the natural anatomy when compared to thecontralateral superior facet 21 of vertebra 16.

[0096] Turning now to FIG. 13, there is provided a perspective view ofvertebra 14 with implanted inferior facet prosthesis 18. Resection 34has removed the natural inferior facet at the bony junction between theinferior facet and the posterior arch 37. In this manner, bone painassociated with a disease, such as osteoarthritis, or trauma may beeliminated inasmuch as the involved bony tissue has been osteotomized.

[0097]FIG. 14 illustrates a perspective view of inferior facetprosthesis 18. Surface 23 replicates the natural articular surface ofthe replaced facet. Flange 25 contacts the pedicle and hole 24 receivesa fastener to attach inferior facet prosthesis 18 to vertebra 14.

[0098]FIG. 15 illustrates a cranial view of vertebra 16 with implantedsuperior facet prosthesis 19. Resection surface 35 represents the bonyjunction between the natural superior facet and the posterior arch 38.

[0099]FIG. 16 illustrates a perspective view of superior facetprosthesis 19. Surface 27 replicates the natural articular surface ofthe replaced facet. Flange 39 contacts the pedicle and hole 26 receivesa fastener to attach inferior facet prosthesis 19 to vertebra 16.

[0100]FIG. 17 illustrates an alternative superior facet prosthesis 40with an bearing surface 41 that mounts to substrate 42. The bearingsurface 41 is a biocompatible polymeric material, such as ultra highmolecular weight polyethylene. Alternately, the bearing surface can beceramic, such as zirconia or alumina, or metal. The substrate is abiocompatible metal alloy, such as an alloy of titanium, cobalt, oriron.

Disc Prosthesis and Double Facet Prosthesis

[0101] Referring next to FIG. 18, there is shown a superior vertebra1005 and an inferior vertebra 1010, with an intervertebral disc 1015located in between. Vertebra 1005 has superior facets 1020, inferiorfacets 1025, a lamina (also sometimes referred to as a posterior arch)1030, a spinous process 1035, and pedicles 1040. Vertebra 1010 hassuperior facets 1045, inferior facets 1050, a posterior arch 1055, aspinous process 1060, and pedicles 1065 (only one of which is seen inFIG. 18).

[0102] Referring now to FIGS. 19 and 20, in accordance with anotheraspect of the invention, intervertebral disc 1015 has been replaced byan artificial disc AD. This artificial disc AD may be a device such asis described by Stefee et al. in U.S. Pat. No. 5,071,437; Gill et al. inU.S. Pat. No. 6,113,637; Bryan et al. in U.S. Pat. No. 6,001,130; Hedmanet al. in U.S. Pat. No. 4,759,769; Ray in U.S. Pat. No. 5,527,312; Rayet al. in U.S. Pat. No. 5,824,093; Buttner-Janz in U.S. Pat. No.5,401,269; and Serhan et al. in U.S. Pat. No. 5,824,094; all whichdocuments are hereby incorporated herein by reference. Alternatively,the artificial disc may be some other artificial disc of the sort knownin the art.

[0103] In addition to the foregoing, the left and right inferior facets1025 of vertebra 1005 have been resected at 1070 and a bilateralinferior facet prosthesis 1075 has been attached to vertebra 1005 usingscrew fasteners 1080. Similarly, the left and right superior facets 1045of vertebra 1010 have been resected at 1082 (FIG. 24) and a bilateralsuperior facet prosthesis 1085 has been attached to vertebra 1010 usingscrew fasteners 1090.

[0104] In FIG. 20 it can be appreciated that bilateral inferior facetprosthesis 1075 replicates the natural anatomy when compared to theintact inferior facet 1025 of vertebra 1005. Furthermore, bilateralfacet prosthesis 1075 extends from its attachment point in a manner thatdoes not require contact with, or mating to, the complex geometry of thelamina (or posterior arch) 1030. Resection surfaces 1070 provideadequate clearance for bilateral inferior facet prosthesis 1075 andprovide complete removal of the diseased or traumatized natural inferiorfacets 1025.

[0105]FIGS. 21 and 22 illustrate how the geometry of the bridge 1095 ofbilateral inferior facet prosthesis 1075 matches that of the posteriorarch 1030 of vertebra 1005 in order to provide adequate clearance forthe central foramen 1100. Articular surfaces 1105 articulate with theopposing superior facets 1045 (or their prosthetic replacements) of thevertebra 1010.

[0106]FIG. 23 illustrates the bilateral inferior facet prosthesis 1075with flanges 1110 that abut against the pedicles 1040 of vertebra 1005.Bridge 1095 connects the articular surfaces 1105. Holes 1115 allow theattachment of bilateral inferior facet prosthesis 1075 to vertebra 1005by means of screw fasteners 1080. Alternatively, screw fasteners 1080could be replaced with staples, pins, tacks, anchors, modular fixationposts, or the like. These alternative fasteners could further includeporous coatings to further enhance bony fixation, and could also includeosteoconductive or osteoinductive substances.

[0107] In FIG. 24 it can be appreciated that bilateral superior facetprosthesis 1085 replicates the natural anatomy when compared to theintact superior facets 1045 of vertebra 1010. Furthermore, bilateralfacet prosthesis 1085 extends from its attachment point in a manner thatdoes not require contact with, or mating to, the complex geometry of thelamina (or posterior arch) 1055. Resection surfaces 1082 provideadequate clearance for bilateral superior facet prosthesis 1085 andprovide complete removal of the diseased or traumatized natural superiorfacets 1045.

[0108]FIG. 25 illustrates how the geometry of the bridge 1120 ofbilateral superior facet prosthesis 1085 matches that of the posteriorarch 1055 of vertebra 1010 in order to provide adequate clearance forthe central foramen 1125. Articular surfaces 1130 articulate with theopposing inferior facets of the vertebra 1005.

[0109]FIG. 26 illustrates the bilateral superior facet prosthesis 1085with flanges 1135 that abut against the pedicles 1065 of vertebra 1010.Bridge 1120 connects the articular surfaces 1130 (seen in FIG. 25 butnot seen in FIG. 26). Holes 1140 allow the attachment of bilateralsuperior facet prosthesis 1085 to vertebra 1010 by means of screwfasteners 1090.

[0110]FIG. 27 illustrates an alternative superior facet prosthesis 1085Awith a bearing surface 1130A that mounts to substrate 1131A. The bearingsurface 1130A is preferably a biocompatible polymeric material, such asultra high molecular weight polyethylene. Alternately, the bearingsurface 1130A can be ceramic, such as zirconia or alumina. The substrate1131A is preferably a biocompatible metal alloy, such as an alloy oftitanium, cobalt, or iron.

[0111]FIG. 28 illustrates a superior vertebra 1145, a middle vertebra1150, and an inferior vertebra 1155. Superior facet prosthesis 1085articulates with quad-facet prosthesis 1160 to recreate the naturalbiomechanics of the replaced facet joints. Inferior facet prosthesis1075 articulates with quad-facet prosthesis 1160 to recreate the naturalbiomechanics of the replaced facet joints at the next upper level. Thus,FIG. 28 illustrates a two level reconstruction of facet joints. Superiorfacet prosthesis 1085, quad-facet prosthesis 1160, and inferior facetprosthesis 1075 are each attached to bone by means of screw fasteners1165.

[0112] In the lateral view of FIG. 29, it can be appreciated thatsuperior facet prosthesis 1085, quad-facet prosthesis 1160, and inferiorfacet prosthesis 1075 do not encroach into the intervertebral foraminalspaces 1167 where nerve roots extend laterally from the spinal cord.

[0113] Referring next to FIG. 30, it should be appreciated that superiorbridge 1170 and inferior bridge 1175 of quad-facet prosthesis 1160 donot contact any portion of vertebra 1150. Mounting holes 1180 (shown inFIG. 31) are used to secure the flanges 1185 against the pedicles ofvertebra 1150.

[0114] In FIG. 32, an alternative inferior bilateral facet prosthesis1190 is presented. To further stabilize the implant and to countermoments that act upon the two points of fixation into the pedicles, aset of parallel flanges 1195 extend posteriorly such that the twoflanges straddle the spinous process 1035. A bolt 1200 is used to fastenthe parallel flanges to the spinous process. Alternatively, otheradjunctive structural features could be added to further stabilize theprosthesis. For example, a strut that extends, and attaches, to thetransverse process could be used to further stabilize the prosthesis.

[0115] Looking next at FIGS. 33 and 34, there is shown a superior andinferior unilateral facet prosthesis 1300. Unilateral facet prosthesis1300 comprises a body 1305 and a stem 1310 extending out of body 1305. Asuperior element 1315 extends vertically upward from body 1305, and aninferior element 1310 extends vertically downward from body 1305.Unilateral facet prosthesis 1300 is configured so that when its stem1310 extends into the pedicle of vertebra 1325, superior element 1315will replace a resected superior facet, and inferior element 1320 willreplace a resected inferior facet. If desired, stem 1310 could bereplaced with a screw extending through a hole in body 1305 and into thepedicle.

Disc Prosthesis and Quadruple Facet Prosthesis

[0116] Referring next to FIG. 35, there is shown a natural lumbarvertebra 2005 comprising a natural vertebral body 2010, a pair ofnatural pedicles 2015 extending from natural vertebral body 2010, anatural lamina 2020 extending from natural pedicles 2015, a pair ofnatural superior facets 2025 extending from natural pedicles 2015 andnatural lamina 2020, a pair of natural inferior facets 2030 extendingfrom natural lamina 2020, a natural spinous process 2035 extending fromnatural lamina 2020, and a pair of natural transverse processes 2040extending from natural pedicles 2015.

[0117] In accordance with another aspect of the invention, theintervertebral disc on one side or the other of vertebral body 2010 isreplaced by an artificial disc. This artificial disc may be a devicesuch as is described by Stefee et al. in U.S. Pat. No. 5,071,437; Gillet al in U.S. Pat. No. 6,113,637; Bryan et al. in U.S. Pat. No.6,001,130; Hedman et al. in U.S. Pat. No. 4,759,769; Ray in U.S. Pat.No. 5,527,312; Ray et al. in U.S. Pat. No. 5,824,093; Buttner-Janz inU.S. Pat. No. 5,401,269; and Serhan et al. in U.S. Pat. No. 5,824,094;all which documents are hereby incorporated herein by reference.Alternatively, the artificial disc may be some other artificial disc ofthe sort known in the art.

[0118] In addition to the foregoing, and looking next at FIGS. 36 and37, there is shown a novel prosthesis 2100 which is adapted to replacethe natural lamina 2020, the two natural superior facets 2025, the twonatural inferior facets 2030, the natural spinous process 2035, and thetwo natural transverse processes 2040. To this end, prosthesis 2100comprises a pair of prosthetic mounts 2115, a prosthetic lamina 2120extending from prosthetic mounts 2115, a pair of prosthetic superiorfacets 2125 extending from prosthetic mounts 2115 and prosthetic lamina2120, a pair of prosthetic inferior facets 2130 extending fromprosthetic lamina 2120, a prosthetic spinous process 2135 extending fromprosthetic lamina 2120, and a pair of prosthetic transverse processes2140 extending from prosthetic mounts 2115.

[0119] In the use of prosthesis 2100, natural lumbar vertebra 2005 isresected at its natural pedicles 2015 so as to remove the natural lamina2020, the two natural superior facets 2025, the two natural inferiorfacets 2030, the natural spinous process 2035, and the two naturaltransverse processes 2040, leaving a pair of pedicle end surfaces 2041(FIG. 38). Then the prosthesis 2100 may be attached to the naturalpedicles 2015, e.g., by placing prosthetic mounts 2115 against pediclesurfaces 2041 and then passing screws 2145 through screw holes 2147 andinto natural pedicles 2015, as shown in FIGS. 39-41. As seen in thedrawings, the relative size, shape and positioning of the prostheticlamina 2120, the two prosthetic superior facets 2125, the two prostheticinferior facets 2130, the prosthetic spinous process 2135, and the twoprosthetic transverse processes 2140 essentially mimic the relativesize, shape and positioning of the natural lamina 2020, the two naturalsuperior facets 2025, the two natural inferior facets 2030, the naturalspinous process 2035, and the two natural transverse processes 2040,whereby to effectively restore the vertebra. If desired, holes 2150 maybe provided in the prosthetic spinous process 2135 and/or the twoprosthetic transverse processes 2140 so as to facilitate re-attachingsoft tissue to these structures.

[0120] Looking next at FIG. 42, there is shown a novel prosthesis 2200which is adapted to replace natural lamina 2020, the two naturalsuperior facets 2025, the two natural inferior facets 2030, and naturalspinous process 2035. To this end, prosthesis 2200 comprises a pair ofprosthetic mounts 2215, a prosthetic lamina 2220 extending fromprosthetic mounts 2215, a pair of prosthetic superior facets 2225extending from prosthetic mounts 2215 and prosthetic lamina 2220, a pairof prosthetic inferior facets 2230 extending from prosthetic lamina2220, and a prosthetic spinous process 2235 extending from prostheticlamina 2220.

[0121] In the use of prosthesis 2200, natural lumbar vertebra 2005 isresected at its natural pedicles 2015 so as to remove the natural lamina2020, the two natural superior facets 2025, the two natural inferiorfacets 2030, the spinous process 2035 and the two natural transverseprocesses 2040, leaving a pair of pedicle surfaces 2041 (FIG. 38). Thenthe prosthesis 2200 may be attached to the natural pedicles 2015, e.g.,by placing prosthetic mounts 2215 against pedicle surfaces 2041 and thenpassing screws 2145 through holes 2247 and into natural pedicles 2015.As seen in the drawing, the relative size, shape and positioning ofprosthetic lamina 2220, the two prosthetic superior facets 2225, the twoprosthetic inferior facets 2230, and the prosthetic spinous process 2235essentially mimic the relative size, shape and positioning of thenatural lamina 2020, the two natural superior facets 2025, the twonatural inferior facets 2030, and the natural spinous process 2035,whereby to effectively restore the vertebra. If desired, holes 2150 maybe provided in the prosthetic spinous process 2235 so as to facilitatere-attaching soft tissue to this structure.

[0122] Looking next at FIG. 43, there is shown a novel prosthesis 2300which is adapted to replace the natural lamina 2020, the two naturalsuperior facets 2025, the two natural inferior facets 2030, and the twonatural transverse processes 2040. To this end, prosthesis 2300comprises a pair of prosthetic mounts 2315, a prosthetic lamina 2320extending from prosthetic mounts 2315, a pair of prosthetic superiorfacets 2325 extending from prosthetic mounts 2315 and prosthetic lamina2320, a pair of prosthetic inferior facets 2330 extending fromprosthetic lamina 2320, and a pair of prosthetic transverse processes2340 extending from prosthetic mounts 2315.

[0123] In the use of prosthesis 2300, natural lumbar vertebra 2005 isresected at natural pedicles 2015 so as to remove natural lamina 2020,the two natural superior facets 2025, the two natural inferior facets2030, the natural spinous process 2035 and the two natural transverseprocesses 2040, leaving a pair of pedicle surfaces 2041 (FIG. 38). Thenthe prosthesis 2300 may be attached to the natural pedicles 2015, e.g.,by placing prosthetic mounts 2315 against pedicle surfaces 2041 and thenpassing screws 2145 through holes 2347 and into natural pedicles 2015.As seen in the drawing, the relative size, shape and positioning of theprosthetic lamina 2320, the two prosthetic superior facets 2325, the twoprosthetic inferior facets 2330, and the two prosthetic transverseprocesses 2340 essentially mimic the relative size, shape andpositioning of the natural lamina 2020, the two natural superior facets2025, the two natural inferior facets 2030, and the two naturaltransverse processes 2040, whereby to effectively restore the vertebra.If desired, holes 2150 may be provided in the two prosthetic transverseprocesses 2340 so as to facilitate re-attaching soft tissue to thesestructures.

[0124] Looking next at FIG. 44, there is shown a novel prosthesis 2400which is adapted to replace the natural lamina 2020, the two naturalsuperior facets 2025, and the two natural inferior facets 2030. To thisend, prosthesis 2400 comprises a pair of prosthetic mounts 2415, aprosthetic lamina 2420 extending from prosthetic mounts 2415, a pair ofprosthetic superior facets 2425 extending from prosthetic mounts 2415and prosthetic lamina 2420, and a pair of prosthetic inferior facets2430 extending from prosthetic lamina 2420.

[0125] In the use of prosthesis 2400, natural lumbar vertebra 2005 isresected at pedicles 2015 so as to remove the natural lamina 2020, thetwo natural superior facets 2025, the two natural inferior facets 2030,the natural spinous process 2035, and the two natural transverseprocesses 2040, leaving a pair of pedicle surfaces 2041 (FIG. 38). Thenthe prosthesis 2400 may be attached to the natural pedicles 2015, e.g.,by placing prosthetic mounts 2415 against pedicle surfaces 2041 and thenpassing screws 2145 through holes 2447 and into natural pedicles 2015.As seen in the drawing, the relative size, shape and positioning ofprosthetic lamina 2420, the two prosthetic superior facets 2425, and thetwo prosthetic inferior facets 2430 essentially mimic the relative size,shape and positioning of the natural lamina 2020, the two naturalsuperior facets 2025 and the two natural inferior facets 2030, wherebyto effectively restore the vertebra.

[0126] Looking next at FIGS. 45-47, there is shown a novel prosthesis2500 which is adapted to replace a pair of natural pedicles 2015, thenatural lamina 2020, the two natural superior facets 2025, the twonatural inferior facets 2030, the natural spinous process 2035, and thetwo natural transverse processes 2040. To this end, prosthesis 2500comprises a pair of prosthetic pedicles 2515, a prosthetic lamina 2520extending from prosthetic pedicles 2515, a pair of prosthetic superiorfacets 2525 extending from prosthetic pedicles 2515 and prostheticlamina 2520, a pair of prosthetic inferior facets 2530 extending fromprosthetic lamina 2520, a prosthetic spinous process 2535 extending fromprosthetic lamina 2520, and a pair of prosthetic transverse processes2540 extending from prosthetic pedicles 2515.

[0127] In the use of prosthesis 2500, natural lumbar vertebra 2005 isresected at the bases of natural pedicles 2015 so as to remove to twonatural pedicles 2015, the natural lumina 2020, the two natural superiorfacets 2025, the two natural inferior facets 2030, the natural spinousprocess 2035, and the two natural transverse processes 2040, leaving avertebral body end face 2042 (FIG. 48). Then the prosthesis 2500 may beattached to the natural vertebral body 2010, e.g., by placing prostheticpedicles 2515 against vertebral body end face 2042 and then passingscrews 2145 through holes 2547 and into natural vertebral body 2010, asshown in FIG. 49. As seen in the drawings, the relative size, shape andpositioning of the two prosthetic pedicles 2515, the prosthetic lamina2520, the two prosthetic superior facets 2525, the two prostheticinferior facets 2530, the prosthetic spinous process 2535, and the twoprosthetic transverse processes 2540 essentially mimic the relativesize, shape and positioning of the two natural pedicles 2015, thenatural lamina 2020, the two natural superior facets 2025, the twonatural inferior facets 2030, the natural spinous process 2035, and thetwo natural transverse processes 2040, whereby to effectively restorethe vertebra. If desired, holes 2150 may be provided in prostheticspinous process 2535 and the two prosthetic transverse processes 2540 soas to facilitate re-attaching soft tissue to these structures.

[0128] Looking next at FIG. 50, there is shown a novel prosthesis 2600which is adapted to replace the two natural pedicles 2015, the naturallamina 2020, the two natural superior facets 2025, the two naturalinferior facets 2030, and the natural spinous process 2035. To this end,prosthesis 2600 comprises a pair of prosthetic pedicles 2615, aprosthetic lamina 2620 extending from prosthetic pedicles 2615, a pairof prosthetic superior facets 2625 extending from prosthetic pedicles2615 and prosthetic lamina 2620, a pair of prosthetic inferior facets2630 extending from prosthetic lamina 2620, and a prosthetic spinousprocess 2635 extending from prosthetic lamina 2620.

[0129] In the use of prosthesis 2600, natural lumbar vertebra 2005 isresected at the bases of natural pedicles 2015 so as to remove the twonatural pedicles 2015, the natural lamina 2020, the two natural superiorfacets 2025, the two natural inferior facets 2030, the natural spinousprocess 2035 and the two natural transverse processes 2040, leaving avertebral body end face 2042 (FIG. 48). Then the prosthesis 2600 may beattached to the natural vertebral body 2010, e.g., by placing prostheticpedicles 2615 against vertebral body end face 2042 and then passingscrews 2145 through holes 2647 and into natural vertebral body 2010. Asseen in the drawing, the relative size, shape and positioning of the twoprosthetic pedicles 2615, the prosthetic lamina 2620, the two prostheticsuperior facets 2625, the two prosthetic inferior facets 2630, and theprosthetic spinous process 2635 essentially mimic the relative size,shape and positioning of the two natural pedicles 2015, the naturallamina 2020, the two natural superior facets 2025, the two naturalinferior facets 2030, and the natural spinous process 2035, whereby toeffectively restore the vertebra. If desired, holes 2150 may be providedin prosthetic spinous process 2635 so as to facilitate re-attaching softtissue to this structure.

[0130] Looking next at FIG. 51, there is shown a novel prosthesis 2700which is adapted to replace the two natural pedicles 2015, the naturallamina 2020, the two natural superior facets 2025, the two naturalinferior facets 2030, and the two natural transverse processes 2040. Tothis end, prosthesis 2700 comprises a pair of prosthetic pedicles 2715,a prosthetic lamina 2720 extending from prosthetic pedicles 2715, a pairof prosthetic superior facets 2725 extending from prosthetic pedicles2715 and prosthetic lamina 2720, a pair of prosthetic inferior facets2730 extending from prosthetic lamina 2720, and a pair of prosthetictransverse processes 2740 extending from prosthetic pedicles 2715.

[0131] In the use of prosthesis 2700, natural lumbar vertebra 2005 isresected at the bases of natural pedicles 2015 so as to remove the twonatural pedicles 2015, the natural lamina 2020, the two natural superiorfacets 2025, the two natural inferior facets 2030, the natural spinousprocess 2035, and the two natural transverse processes 2040, leaving avertebral body end face 2042 (FIG. 48). Then the prosthesis 2700 may beattached to the natural vertebral body 2010, e.g., by placing prostheticpedicles 2715 against vertebral body end face 2042 and then passingscrews 2145 through holes 2747 and into vertebral body 2010. As seen inthe drawing, the relative size, shape and positioning of the twoprosthetic pedicles 2715, the prosthetic lamina 2720, the two prostheticsuperior facets 2725, the two prosthetic inferior facets 2730, and thetwo prosthetic transverse processes 2740 essentially mimic the relativesize, shape and positioning of the two natural pedicles 2015, thenatural lamina 2020, the two natural superior facets 2025, the twonatural inferior facets 2030, and the two natural transverse processes2040, whereby to effectively restore the vertebra. If desired, holes2150 may be provided in the two prosthetic transverse processes 2740 soas to facilitate re-attaching soft tissue to these structures.

[0132] Looking next at FIG. 52, there is shown a novel prosthesis 2800which is adapted to replace the two natural pedicles 2015, the naturallamina 2020, the two natural superior facets 2025, and the two naturalinferior facets 2030. To this end, prosthesis 2800 comprises a pair ofprosthetic pedicles 2815, a prosthetic lamina 2820 extending fromprosthetic pedicles 2815, a pair of prosthetic superior facets 2825extending from prosthetic pedicles 2815 and prosthetic lamina 2820, anda pair of prosthetic inferior facets 2830 extending from prostheticlamina 2820.

[0133] In the use of prosthesis 2800, natural lumbar vertebra 2005 isresected at the bases of natural pedicles 2015 so as to remove the twonatural pedicles 2015, the natural lamina 2020, the two natural superiorfacets 2025, the two natural inferior facets 2030, the natural spinousprocess 2035, and the two natural transverse processes 2040, leaving avertebral body end face 2042 (FIG. 48). Then the prosthesis 2800 may beattached to natural vertebral body 2010, e.g., by placing prostheticpedicles 2715 against vertebral body end face 2042 and then passingscrews 2145 through holes 2847 and into natural vertebral body 2010. Asseen in the drawing, the relative size, shape and positioning of the twoprosthetic pedicles 2815, the prosthetic lamina 2820, the two prostheticsuperior facets 2825, and the two prosthetic inferior facets 2830essentially mimic the relative size, shape and positioning of the twonatural pedicles 2015, the natural lamina 2020, the two natural superiorfacets 2025, and the two natural inferior facets 2030, whereby toeffectively restore the vertebra.

[0134] It should also be appreciated that prostheses 2100, 2200, 2300,2400, 2500, 2600, 2700 and 2800 may be attached to natural vertebra 2005with apparatus other than the screws 2145 discussed above. Thus, forexample, prostheses 2100, 2200, 2300, 2400, 2500, 2600, 2700 and 2800may be attached to natural vertebra 2005 with rods or posts, etc. See,for example, FIG. 53, where prosthesis 2500 is shown attached to naturalvertebra 2005 with rods 2146 which pass through, and snap intoengagement with, prosthetic pedicles 2515.

[0135] Having thus described preferred embodiments of the invention withreference to the accompanying drawings, it is to be understood that theembodiments shown herein are provided by way of example only, and thatvarious changes and modifications may be effected by one skilled in theart without departing from the scope or spirit of the invention asdefined in the claims.

What is claimed is:
 1. A kit for spine joint replacement comprising: anartificial disc; and a prosthesis for the replacement of at least aportion of the bone of a facet located on a mammalian vertebra,comprising: a surface that articulates with an other facet surface; anda fixation portion that is implanted into an interior bone space of saidvertebra, said surface being connected to said fixation portion; whereinsaid artificial disc and said prosthesis cooperate so as to restore thenatural biomechanics of a spinal motion segment.
 2. The kit of claim 1wherein said fixation portion is a post that is adapted to be fittedinto the interior bone space of a pedicle.
 3. The kit of claim 2 whereinsaid post is porous coated to allow for bone ingrowth.
 4. The kit ofclaim 3 wherein said porous coating includes osteoconductive orosteoinductive substances.
 5. The kit of claim 1 wherein said fixationportion is a fin that is adapted to be fitted into the interior bonespace of the posterior arch.
 6. The kit of claim 5 wherein said fin isporous coated to allow for bone ingrowth.
 7. The kit of claim 6 whereinsaid porous coating includes osteoconductive or osteoinductivesubstances.
 8. The kit of claim 1 wherein said surface that articulatesis comprised of one of a group consisting of a polymeric bearingmaterial attached to a metal substrate, a ceramic bearing material, anda metal bearing material.
 9. A kit for spine joint replacementcomprising: an artificial disc; and a prosthesis for the replacement ofat least a portion of the bone of a facet located on a mammalianvertebra, comprising: a surface that articulates with another facet; abone contacting surface that contacts one of an exterior surface or aresected surface of said vertebra, said surface that articulates beingconnected to said bone contacting surface; and a fixation element thatattaches said bone contacting surface to said vertebra; and wherein saidprosthesis is configured so that no portion of said prosthesis contactsthe posterior arch of said vertebra; and wherein said artificial discand said prosthesis cooperate so as to restore the natural biomechanicsof a spinal motion segment.
 10. The kit of claim 9 wherein said fixationelement is a screw.
 11. The kit of claim 9 wherein said flange has abone side adapted to contact one of said exterior surface or saidresected surface of said vertebra, wherein said bone side is porouscoated to allow for bone ingrowth.
 12. The kit of claim 9 wherein saidsurface that articulates is comprised of one of a group consisting of apolymeric bearing material attached to a metal substrate, a ceramicbearing material, and a metal bearing material.
 13. A kit for spinejoint replacement comprising: an artificial disc; and a prosthesis forthe replacement of at least a portion of the bones of opposed andarticulating facets located on a mammalian vertebra, where said facetsare diseased or traumatized, comprising: an inferior component adaptedto be attached to a first vertebra and having a first fixation portionadapted to be implanted into a first interior bone space and a firstarticulation portion connected to said first fixation portion; asuperior component adapted to be attached to a second vertebra andhaving a second fixation portion adapted to be implanted into a secondinterior bone space and second articulation portion connected to saidsecond fixation portion; where the first vertebra is adjacent andsuperior to the second vertebra; and wherein said artificial disc andsaid prosthesis cooperate so as to restore the natural biomechanics of aspinal motion segment.
 14. A kit for spine joint replacement comprising:an artificial disc; and a prosthesis for the replacement of at least aportion of the bones of opposed and articulating facets located on amammalian vertebra, comprising: an inferior component adapted to beattached to a first vertebra; and a superior component adapted to beattached to a second vertebra; where the first vertebra is adjacent andsuperior to the second vertebra; and where one of said inferior andsuperior components includes: a flange that connects to one of anexterior surface or a resected surface of said vertebra; and a fixationelement that attaches said flange to said vertebra; and further whereinof said prosthesis is configured so that no portion of said prosthesiscontacts the posterior arch of said vertebra; and wherein saidartificial disc and said prosthesis cooperate so as to restore thenatural biomechanics of a spinal motion segment.
 15. A method forreplacing a spine joint, comprising the steps of: replacing anintervertebral disc with an artificial disc; resecting at least aportion of the bone of a facet; attaching a prosthetic facet to theremaining bone of said vertebra such that no portion of the prostheticfacet contacts the posterior arch of said vertebra; where saidprosthetic facet is adapted to articulate with another facet; with theartificial disc and the prosthetic facet cooperating so as to restorethe natural biomechanics of a spinal motion segment.
 16. A method forreplacing a spine joint, comprising the steps of: replacing anintervertebral disc with an artificial disc; resecting at least aportion of the bone of a first facet on a first vertebra; attaching afirst prosthetic facet to the remaining bone of said first vertebra suchthat no portion of said prosthetic facet contacts the posterior arch ofsaid vertebra; resecting at least a portion of the bone of a secondfacet on a second vertebra; and attaching a second prosthetic facet tothe remaining bone of said second vertebra such that no portion of saidprosthetic facet contacts the posterior arch of said vertebra; wheresaid first prosthetic facet is adapted to articulate with said secondprosthetic facet; with the artificial disc and the prosthetic facetcooperating so as to restore the natural biomechanics of a spinal motionsegment.
 17. A kit for spine joint replacement, comprising: anartificial disc; and a prosthesis for the replacement of at least twofacets located on a mammalian vertebra, comprising: at least one bonecontacting surface that is adapted to be secured to a surface of thevertebra; and at least two bearing surfaces for articulating with otherfacets, said at least two bearing surfaces being connected to said atleast one bone contacting surface; and wherein no portion of saidprosthesis is supported by the lamina of the vertebra; and wherein saidartificial disc and said prosthesis cooperate so as to restore thenatural biomechanics of a spinal motion segment.
 18. The kit of claim 17further comprising fixation elements for securing said at least one bonecontacting surface to the vertebra.
 19. The kit of claim 18 wherein saidfixation elements are screws.
 20. The kit of claim 17 wherein said atleast bone contacting surface is porous coated to allow for boneingrowth.
 21. The kit of claim 20 wherein said porous coating includesat least one from a group comprising osteoinductive and osteoconductivesubstances.
 22. The kit of claim 17 wherein said bearing surfaces areformed from a material selected from the group consisting of a ceramic,a metal and a polymer.
 23. The kit of claim 17 wherein said prosthesisis configured so that said at least two bearing surfaces are adapted toreplace a pair of inferior facets.
 24. The kit of claim 17 wherein saidprosthesis is configured so that said at least two bearing surfaces areadapted to replace a pair of superior facets.
 25. The kit of claim 17wherein said prosthesis is configured so that said at least two bearingsurfaces are adapted to replace an inferior facet and a superior facet.26. The kit of claim 17 wherein said prosthesis is configured so thatsaid at least two bearing surfaces are adapted to replace a pair ofinferior facets and a pair of superior facets.
 27. A method forreplacing a spine joint, comprising the steps of: replacing anintervertebral disc with an artificial disc; resecting a pair of facetson the vertebra; and attaching a prosthesis to the vertebra so that apair of bearing surfaces on the prosthesis are positioned in place ofthe resected facets, wherein the prosthesis is configured so that noportion of said prosthesis is supported by the lamina of the vertebra;with the artificial disc and the prosthesis cooperating so as to restorethe natural biomechanics of a spinal motion segment.
 28. A method forreplacing a spine joint, comprising the steps of: replacing anintervertebral disc with an artificial disc; resecting at least a bonyportion of the inferior facets of a superior vertebra; attaching a firstprosthesis that replaces said inferior facets of said superior vertebra;resecting at least a bony portion of the superior facets of an inferiorvertebra; and attaching a second prosthesis that replaces said superiorfacets of said inferior vertebra; wherein no portion of said firstprosthesis is supported by the lamina of said superior vertebra, andfurther wherein no portion of said second prosthesis is supported by thelamina of said inferior vertebra; with the artificial disc and the firstprosthesis and the second prosthesis cooperating so as to restore thenatural biomechanics of a spinal motion segment.
 29. A method forreplacing a spine joint, comprising the steps of: replacing anintervertebral disc with an artificial disc; resecting at least a bonyportion of the inferior facets of a most superior vertebra; attaching afirst prosthesis that replaces said inferior facets of said mostsuperior vertebra; resecting at least a bony portion of the superiorfacets of a most inferior vertebra; attaching a second prosthesis thatreplaces said superior facets of said most inferior vertebra; resectingat least a bony portion of all of the facets of at least oneintermediate vertebra located between said most superior vertebra andsaid most inferior vertebra; wherein, for each of said at least oneintermediate vertebra, a prosthesis is attached that replaces all facetsof said intermediate vertebra; with the artificial disc and theprostheses cooperating so as to restore the natural biomechanics of aspinal motion segment.
 30. A spinal implant kit comprising: anartificial disc; and one facet prosthesis adapted to replace twosuperior facets; one facet prosthesis adapted to replace two inferiorfacets; and one facet prosthesis adapted to replace two superior facetsand two inferior facets; with the artificial disc and the prosthesescooperating so as to restore the natural biomechanics of a spinal motionsegment.
 31. A kit for spine joint replacement comprising: an artificialdisc; and a prosthesis for the replacement of a pair of spinal facets,said prosthesis comprising: a first vertical member having a first endand a second end, said first end being adapted for disposition against,and attachment to, a first pedicle of a vertebra, and said second endcomprising a bearing surface for engagement with a facet of an adjacentvertebra; a second vertical member having a first end and a second end,said first end being adapted for disposition against, and attachment to,the other pedicle of the vertebra, said second end comprising a bearingsurface with a facet of an adjacent vertebra; and a bridge connectingsaid second end of said first vertical member to said second end of saidsecond vertical member; with the artificial disc and the prosthesiscooperating so as to restore the natural biomechanics of a spinal motionsegment.
 32. The kit of claim 31 wherein said first vertical member,said second vertical member and said bridge are formed so that saidprosthesis is displaced from the lamina of the vertebra when said firstend of said first vertical member is disposed against, and attached to,the first pedicle of a vertebra and said first end of said secondvertical member is disposed against, and attached to, the other pedicleof the vertebra.
 33. A spinal implant kit comprising: an artificialdisc; and a superior facet prosthesis adapted to replace two superiorfacets; an inferior facet prosthesis adapted to replace two inferiorfacets; wherein no portion of said superior facet prosthesis issupported by a lamina of a vertebra; and wherein no portion of saidinferior facet prosthesis is supported by a lamina of a vertebra; withthe artificial disc and the prosthesis cooperating so as to restore thenatural biomechanics of a spinal motion segment.
 34. A kit for spinejoint replacement comprising: an artificial disc; and a prosthesis forthe replacement of a pair of spinal facets, said prosthesis comprising:a first vertical member having a first end and a second end, said firstend being adapted for disposition against, and attachment to, a firstpedicle of a vertebra, and said second end comprising a bearing surfacefor engagement with a facet of an adjacent vertebra; a second verticalmember having a first end and a second end, said first end being adaptedfor disposition against, and attachment to, the other pedicle of thevertebra, said second end comprising a bearing surface with a facet ofan adjacent vertebra; and a bridge connecting said first vertical memberto said second vertical member; wherein said first vertical member, saidsecond vertical member and said bridge are formed so that saidprosthesis is displaced from the lamina of the vertebra when said firstend of said first vertical member is disposed against, and attached to,the first pedicle of a vertebra and said first end of said secondvertical member is disposed against, and attached to, the other pedicleof the vertebra; with the artificial disc and the prosthesis cooperatingso as to restore the natural biomechanics of a spinal motion segment.35. A kit for spine joint replacement comprising: an artificial disc;and a prosthesis for the replacement of a posterior element of a naturalvertebra, wherein the natural vertebra comprises a natural vertebralbody, a pair of natural pedicles extending from the natural vertebralbody, a natural lamina extending from the two natural pedicles, a pairof natural superior facets extending from the two natural pedicles andthe natural lamina, a pair of natural inferior facets extending from thenatural lamina, a natural spinous process extending from the naturallamina, and a pair of natural transverse processes extending from thetwo natural pedicles, said prosthesis comprising: a pair of prostheticmounts; a prosthetic lamina extending from said two prosthetic mounts; apair of prosthetic superior facets extending from said two prostheticmounts and said prosthetic lamina; a pair of prosthetic inferior facetsextending from said prosthetic lamina; a prosthetic spinous processextending from said prosthetic lamina; and a pair of prosthetictransverse processes extending from said two prosthetic mounts; with theartificial disc and the prosthesis cooperating so as to restore thenatural biomechanics of a spinal motion segment.
 36. The kit of claim 35wherein at least one of said prosthetic spinous process and said twoprosthetic transverse processes includes at least one opening forattaching soft tissue to said prosthesis.
 37. The kit of claim 35wherein said two prosthetic mounts comprise openings for attaching saidprosthesis to the natural vertebra.
 38. A kit for spine jointreplacement comprising: an artificial disc; and a prosthesis for thereplacement of a posterior element of a natural vertebra, wherein thenatural vertebra comprises a natural vertebral body, a pair of naturalpedicles extending from the natural vertebral body, a natural laminaextending from the two natural pedicles, a pair of natural superiorfacets extending from the two natural pedicles and the natural lamina, apair of natural inferior facets extending from the natural lamina, anatural spinous process extending from the natural lamina, and a pair ofnatural transverse processes extending from the two natural pedicles,said prosthesis comprising: a pair of prosthetic mounts; a prostheticlamina extending from said two prosthetic mounts; a pair of prostheticsuperior facets extending from said two prosthetic mounts and saidprosthetic lamina; a pair of prosthetic inferior facets extending fromsaid prosthetic lamina; and a prosthetic spinous process extending fromsaid prosthetic lamina; with the artificial disc and the prosthesiscooperating so as to restore the natural biomechanics of a spinal motionsegment.
 39. The kit of claim 38 wherein said prosthetic spinous processincludes at least one opening for attaching soft tissue to saidprosthesis.
 40. The kit of claim 38 wherein said two prosthetic mountscomprise openings for attaching said prosthesis to the natural vertebra.41. A kit for spine joint replacement comprising: an artificial disc;and a prosthesis for the replacement of a posterior element of a naturalvertebra, wherein the natural vertebra comprises a natural vertebralbody, a pair of natural pedicles extending from the natural vertebralbody, a natural lamina extending from the two natural pedicles, a pairof natural superior facets extending from the two natural pedicles andthe natural lamina, a pair of natural inferior facets extending from thenatural lamina, a natural spinous process extending from the naturallamina, and a pair of natural transverse processes extending from thetwo natural pedicles, said prosthesis comprising: a pair of prostheticmounts; a prosthetic lamina extending from said two prosthetic mounts; apair of prosthetic superior facets extending from said two prostheticmounts and said prosthetic lamina; a pair of prosthetic inferior facetsextending from said prosthetic lamina; and a pair of prosthetictransverse processes extending from said two prosthetic mounts; with theartificial disc and the prosthesis cooperating so as to restore thenatural biomechanics of a spinal motion segment.
 42. The kit of claim 41wherein at least one of said two prosthetic transverse processesincludes at least one opening for attaching soft tissue to saidprosthesis.
 43. The kit of claim 41 wherein said two prosthetic mountscomprise openings for attaching said prosthesis to the natural vertebra.44. A kit for spine joint replacement comprising: an artificial disc;and a prosthesis for the replacement of a posterior element of a naturalvertebra, wherein the natural vertebra comprises a natural vertebralbody, a pair of natural pedicles extending from the natural vertebralbody, a natural lamina extending from the two natural pedicles, a pairof natural superior facets extending from the two natural pedicles andthe natural lamina, a pair of natural inferior facets extending from thenatural lamina, a natural spinous process extending from the naturallamina, and a pair of natural transverse processes extending from thetwo natural pedicles, said prosthesis comprising: a pair of prostheticmounts; a prosthetic lamina extending from said two prosthetic mounts; apair of prosthetic superior facets extending from said two prostheticmounts and said prosthetic lamina; and a pair of prosthetic inferiorfacets extending from said prosthetic lamina; with the artificial discand the prosthesis cooperating so as to restore the natural biomechanicsof a spinal motion segment.
 45. The kit of claim 44 wherein said twoprosthetic mounts comprise openings for attaching said prosthesis to thenatural vertebra.
 46. A kit for spine joint replacement comprising: anartificial disc; and a prosthesis for the replacement of a posteriorelement of a natural vertebra, wherein the natural vertebra comprises anatural vertebral body, a pair of natural pedicles extending from thenatural vertebral body, a natural lamina extending from the two naturalpedicles, a pair of natural superior facets extending from the twonatural pedicles and the natural lamina, a pair of natural inferiorfacets extending from the natural lamina, a natural spinous processextending from the natural lamina, and a pair of natural transverseprocesses extending from the two natural pedicles, said prosthesiscomprising: a pair of prosthetic pedicles; a prosthetic lamina extendingfrom said two prosthetic pedicles; a pair of prosthetic superior facetsextending from said two prosthetic pedicles and said prosthetic lamina;a pair of prosthetic inferior facets extending from said prostheticlamina; a prosthetic spinous process extending from said prostheticlamina; and a pair of prosthetic transverse processes extending fromsaid two prosthetic pedicles; with the artificial disc and theprosthesis cooperating so as to restore the natural biomechanics of aspinal motion segment.
 47. The kit of claim 46 wherein at least one ofsaid prosthetic spinous process and said two prosthetic transverseprocesses includes at least one opening for attaching soft tissue tosaid prosthesis.
 48. The kit of claim 46 wherein said two prostheticpedicles comprise openings for attaching said prosthesis to the naturalvertebra.
 49. A kit for spine joint replacement comprising: anartificial disc; and a prosthesis for the replacement of a posteriorelement of a natural vertebra, wherein the natural vertebra comprises anatural vertebral body, a pair of natural pedicles extending from thenatural vertebral body, a natural lamina extending from the two naturalpedicles, a pair of natural superior facets extending from the twonatural pedicles and the natural lamina, a pair of natural inferiorfacets extending from the natural lamina, a natural spinous processextending from the natural lamina, and a pair of natural transverseprocesses extending from the two natural pedicles, said prosthesiscomprising: a pair of prosthetic pedicles; a prosthetic lamina extendingfrom said two prosthetic pedicles; a pair of prosthetic superior facetsextending from said two prosthetic pedicles and said prosthetic lamina;a pair of prosthetic inferior facets extending from said prostheticlamina; and a prosthetic spinous process extending from said prostheticlamina; with the artificial disc and the prosthesis cooperating so as torestore the natural biomechanics of a spinal motion segment.
 50. The kitof claim 49 wherein said prosthetic spinous process includes at leastone opening for attaching soft tissue to said prosthesis.
 51. The kit ofclaim 49 wherein said two prosthetic pedicles comprise openings forattaching said prosthesis to the natural vertebra.
 52. A kit for spinejoint replacement comprising: an artificial disc; and a prosthesis forthe replacement of a posterior element of a natural vertebra, whereinthe natural vertebra comprises a natural vertebral body, a pair ofnatural pedicles extending from the natural vertebral body, a naturallamina extending from the two natural pedicles, a pair of naturalsuperior facets extending from the two natural pedicles and the naturallamina, a pair of natural inferior facets extending from the naturallamina, a natural spinous process extending from the natural lamina, anda pair of natural transverse processes extending from the two naturalpedicles, said prosthesis comprising: a pair of prosthetic pedicles; aprosthetic lamina extending from said two prosthetic pedicles; a pair ofprosthetic superior facets extending from said two prosthetic pediclesand said prosthetic lamina; a pair of prosthetic inferior facetsextending from said prosthetic lamina; and a pair of prosthetictransverse processes extending from said two prosthetic pedicles; withthe artificial disc and the prosthesis cooperating so as to restore thenatural biomechanics of a spinal motion segment.
 53. The kit of claim 52wherein at least one of said two prosthetic transverse processesincludes at least one opening for attaching soft tissue to saidprosthesis.
 54. The kit of claim 52 wherein said two prosthetic pediclescomprise openings for attaching said prosthesis to the natural vertebra.55. A kit for spine joint replacement comprising: an artificial disc;and a prosthesis for the replacement of a posterior element of a naturalvertebra, wherein the natural vertebra comprises a natural vertebralbody, a pair of natural pedicles extending from the natural vertebralbody, a natural lamina extending from the two natural pedicles, a pairof natural superior facets extending from the two natural pedicles andthe natural lamina, a pair of natural inferior facets extending from thenatural lamina, a natural spinous process extending from the naturallamina, and a pair of natural transverse processes extending from thetwo natural pedicles, said prosthesis comprising: a pair of prostheticpedicles; a prosthetic lamina extending from said two prostheticpedicles; a pair of prosthetic superior facets extending from said twoprosthetic pedicles and said prosthetic lamina; and a pair of prostheticinferior facets extending from said prosthetic lamina; with theartificial disc and the prosthesis cooperating so as to restore thenatural biomechanics of a spinal motion segment.
 56. The kit of claim 55wherein said two prosthetic pedicles comprise openings for attachingsaid prosthesis to the natural vertebra.
 57. A method for replacing aspine joint, wherein the natural vertebra comprises a natural vertebralbody, a pair of natural pedicles extending from the natural vertebralbody, a natural lamina extending from the two natural pedicles, a pairof natural superior facets extending from the two natural pedicles andthe natural lamina, a pair of natural inferior facets extending from thenatural lamina, a natural spinous process extending from the naturallamina and a pair of natural transverse processes extending from the twonatural pedicles, said method comprising the steps of: replacing anintervertebral disc with an artificial disc; making a resection at themost dorsal aspect the two natural pedicles; and attaching a prosthesisto the resected vertebra, said prosthesis comprising a pair ofprosthetic mounts, a prosthetic lamina extending from said twoprosthetic mounts, a pair of prosthetic superior facet extending fromsaid two prosthetic mounts and said prosthetic lamina, and a pair ofprosthetic inferior facets extending from said prosthetic lamina; withthe artificial disc and the prosthesis cooperating so as to restore thenatural biomechanics of a spinal motion segment.
 58. A method accordingto claim 57 wherein said prosthesis further comprises a prostheticspinous process extending from said prosthetic lamina.
 59. A methodaccording to claim 57 wherein said prosthesis further comprises a pairof prosthetic transverse processes extending from said two prostheticmounts.
 60. A method according to claim 57 wherein said prosthesisfurther comprises a prosthetic spinous process extending from saidprosthetic lamina and a pair of prosthetic transverse processesextending from said two prosthetic mounts and said prosthetic lamina.61. A method for replacing a spine joint, wherein the natural vertebracomprises a natural vertebral body, a pair of natural pedicles extendingfrom the natural vertebral body, a natural lamina extending from the twonatural pedicles, a pair of natural superior facets extending from thetwo natural pedicles and the natural lamina, a pair of natural inferiorfacets extending from the natural lamina, a natural spinous processextending from the natural lamina, and a pair of natural transverseprocesses extending from the natural pedicles, said method comprisingthe steps of: replacing an intervertebral disc with an artificial disc;making a resection at the junction of the natural vertebral body and thetwo natural pedicles; and attaching a prosthesis to the resectedvertebra, said prosthesis comprising a pair of prosthetic pedicles, aprosthetic lamina extending from said prosthetic pedicles, a pair ofprosthetic superior facets extending from said two prosthetic pediclesand said prosthetic lamina, and a pair of prosthetic inferior facetsextending from said prosthetic lamina; with the artificial disc and theprosthesis cooperating so as to restore the natural biomechanics of aspinal motion segment.
 62. A method according to claim 61 wherein saidprosthesis further comprises a prosthetic spinous process extending fromsaid prosthetic lamina.
 63. A method according to claim 61 wherein saidprosthesis further comprises a pair of prosthetic transverse processesextending from said two prosthetic pedicles.
 64. A method according toclaim 61 wherein said prosthesis further comprises a prosthetic spinousprocess extending from said prosthetic lamina and two prosthetictransverse processes extending from said two prosthetic pedicles andsaid prosthetic lamina.